Nearly £25 million-worth of attempted fraud has been prevented due to a rapid response scheme which sees bank branch staff contact police if they suspect a customer is in the process of being scammed.
The Banking Protocol means bank and building society branch staff can alert police to suspected frauds taking place, knowing they will receive an immediate priority response.
Figures from trade association UK Finance show £24.7 million of fraud has been prevented and 197 arrests made due to the introduction of the Banking Protocol.
The average fraud prevention per call equates to £6,720.
UK Finance has led the development and implementation of the Banking Protocol - which is a partnership between the finance industry and police supported by National Trading Standards and the Joint Fraud Taskforce.
Under the scheme, if someone visits a branch and asks to withdraw or transfer an amount of cash which appears unusual for them, branch staff will politely ask about the reasons for the transaction.
If staff suspect the customer is potentially going be a victim of fraud, they can call 999 and there will be an immediate priority response to the branch by police.
As well as preventing the fraud, this potentially facilitates the arrest of the fraudster.
Previously, while branch staff could contact police, the response received would vary greatly from one police force to another, UK Finance said.
The new system means that a priority response is guaranteed - and branch staff can be confident to call the police and know that if they have a customer waiting, the police will be there soon.
Some 48 financial organisations, including the Post Office, are committed to the Banking Protocol nationally. Any organisation proving banking facilities with a branch network can join the scheme for free.
A national rollout of the scheme began in May 2017, following a pilot in London launched in October 2016.
The most recent figures show that the scheme prevented over £3 million in fraud in May 2018 - a monthly record.
As well as stopping frauds taking place, the scheme ensures a consistent response to potential victims and gives them extra support to prevent them becoming a victim in the future.
Katy Worobec, managing director of economic crime at UK Finance, said: "Fraud can have a devastating impact on victims and is often targeted at the most vulnerable people in society, which is why we must work together to prevent it.
"The Banking Protocol shows how close co-operation between the industry and law enforcement can help to protect victims and crack down on fraudsters.
"This kind of joined-up approach is crucial to stay one step ahead and ensure that unscrupulous scammers preying on customers are brought to justice."
Detective Chief Superintendent Glenn Maleary, head of the City of London Police's Economic Crime Directorate, said: "The scale and borderless nature of fraud means we are having to find new and innovative ways to protect the public and deter the criminals.
"Banks are often the first point of contact for someone who is about to fall victim to fraud, so the Banking Protocol is a vital way of protecting vulnerable victims and preventing fraudsters from taking advantage of them.
"Since it was initiated, the Protocol has built its strength and though it is now preventing people losing millions of pounds to fraudsters, we have to remain vigilant to changing criminal trends and adapt accordingly."